Equisetum variegatum; The Variegated Horsetail is very common. It grows almost everywhere on Iceland, but for the glaciers. It can be distinguished from other (more or less unbranched-) horsetails by angled stems with dentated sheaths (5-8) with conspicuous membrane fringes and the pointed spore tops. grows in bogs and marshlands. The main branch has only very short side branches. The Icelandic name is Beitieski. Next to the variegated horsetail some other similar horsetails grow on Iceland. To tell them apart here is a simple key:
- E. arvense, field horsetail: the sporangial cones appear very early in spring on colorless stems before the green stems. The green stems typically have side branches pointed upwards.
- E. pratense, shady horsetail: characteristic are the horizontal, even drooping downwards of the lateral branches. The sporangial cones, however, appear on at first on top of unbranched main stems which form the lateral branches later as the spores mature.
- E. palustre: marsh horsetail: short side branches, terminal cones not pointed, about 13 dental points on stem-sheaths.
- E. fluviatile: water horsetail: no side branches, terminal cones not pointed, about 14 dental points on stem-sheaths.
- E. variegatum: variegated horsetail: no side branches, terminal cones pointed, about 5-8 dental points on stem-sheaths.
- E. hyemale: rough horsetail: no side branches, about 20 dental points on stem-sheath - but very tiny: the sheaths seems almost round. Much thicker stems than any other horsetail on Iceland.